Relationship experts have long said that subtly mimicking another's body language is smart -- it gains their trust, and makes them feel comfortable.

However, University of California-San Diego researchers have cautioned against too much imitation, in a study soon to be published in Psychological Science, reports the Daily Mail.

Study participants were asked to watch and rate several video-taped job interviews. Though they weren't told to be pay attention to body language, they resoundingly found interviewees who mirrored their interviewer (in an obvious way) to be less trustworthy and more incompetent.

"Mimicry is a crucial part of social intelligence," UC-San Diego psychology professor Piotr Winkielman tells the Mail. "But it is not enough to simply know how to mimic.

"It's also important to know when and when not to. The success of mirroring depends on mirroring the right people at the right time for the right reasons. Sometimes the intelligent thing to do is not to imitate."